Chromate Free Corrosion Resistant Coatings using Water-Dispersible Tannisulfonic Acid-Doped Conducting Polymers and Nanocomposites (TSE03-B)

对转化膜中挥发性有机化合物(VOCs)和重金属(如铬)的持续限制使得寻找新的替代品变得必要。尽管人们很早就知道本征导电聚合物(ICP)可以抑制金属的腐蚀过程，但它们的不溶性限制了它们在工业上的应用(欧洲的Ormecon除外)。该项目中提议的ICP将利用可再生资源材料单宁酸作为模板/掺杂剂来生产水分散体系。由于单宁具有防止腐蚀的已知能力，单宁酸掺杂的ICPS应该提供环境友好的缓蚀剂。由于邻苯二酚基团的存在和某些金属氧基纳米复合材料本身对腐蚀的抑制作用，单宁对金属离子的络合作用是已知的，因此将合成与单宁酸螯合的金属氧基纳米复合材料。这些基于单宁的纳米复合材料将被用作模板/掺杂剂，用于合成新型的水分散ICP。作为协同效应的结果，这些缓蚀剂可能被证明是非常有效的。合成的ICP将用各种光谱和电化学方法进行表征。那些表现出足够的导电性、电活性和分散性的树脂将与各种水性商业树脂混合，并应用于各种基材上，包括工业上常用的铁和铝合金。将根据ASTM标准进行基材准备和涂层应用。腐蚀测试将使用电化学腐蚀技术，如电化学阻抗谱、循环极化和塔菲尔曲线。这些测试的结果将直接与传统的阻挡层和包括铬酸盐在内的转化涂层进行比较。更广泛的影响由于可以在涂料工业中使用大量的ICP，导电聚合物的未来很可能取决于它们在缓蚀方面的成功。此外，在这项研究中产生的数据将有助于阐明仍然在某种程度上难以捉摸的防腐机理。使用可再生资源作为有毒重金属的替代品，并在不牺牲防腐涂料所需性能的情况下减少VOCs，这一概念在环境和经济上都很有吸引力，非常符合NSF/EPA项目的范围。学生参与这个项目为他们提供了参与对环境具有重要意义的尖端研究的机会，包括从源头上消除铬酸盐和挥发性有机化合物，同时培训他们成为聚合物化学家。ICPS在生物医学领域，特别是在神经再生和人工肌肉领域已经显示出良好的前景。将作出协调一致的努力，让附近医学院的研究界成员参加讲习班和研讨会，以便将来有可能与我们小组开展合作项目。

Continuing restrictions on volatile organic compounds (VOCs) and heavy metals such as chromium in conversion coatings have made it necessary to search for novel alternatives. Although inherently conducting polymers (ICPs) have long been known to inhibit the corrosion process of metals, their use in industry (with the exception of Ormecon in Europe) has been limited by their insolubility. The ICPs proposed in this project will utilize tanninsulfonic acid, a renewable resource material, as a template/dopant to yield water-dispersible systems. Due to the already known ability of tannin to prevent corrosion, tanninsulfonic acid-doped ICPs should provide environmentally friendly corrosion inhibitors. Since tannins are known to complex metal ions efficiently due to the presence of the o-catechol groups and the fact that certain metal oxo nanocomposites themselves have been shown to inhibit corrosion, metal oxo nanocomposites chelated to tanninsulfonic acid will be synthesized. These tannin based nanocomposites will be used as templates/dopants for the synthesis of novel water-dispersible ICPs. As a result of the synergistic effects, these corrosion inhibitors may prove to be highly effective. The synthesized ICPs will be characterized using various spectroscopic and electrochemical methods. Those that show sufficient conductivity, electroactivity, and dispersibility will be blended with a variety of water-based commercial resins and applied on a variety of substrates including alloys of iron and aluminum that are commonly used in industry. Substrate preparation and coating application will be performed according to ASTM standards. Corrosion testing will be performed using electrochemical corrosion techniques such as electrochemical impedance spectroscopy, cyclic polarization and Tafel plots. The results from these tests will be directly compared with conventional barrier and conversion coatings including chromates. Broader ImpactDue to the high volume of ICPs that could be used in the coating industry, the future of conducting polymers may well lie in their success in corrosion inhibition. In addition, the data generated during this research will be helpful in elucidating the mechanism of corrosion prevention which still remains somewhat elusive. The concept of using a renewable resource as a substitute for a toxic heavy metal as well as in reducing VOCs without sacrificing desirable properties in corrosion resistant coatings is both environmentally and economically appealing and fits well with the scope of this NSF/EPA project. The involvement of students in this project provides them an opportunity to be involved in cutting edge research of importance to the environment that includes elimination of chromates and VOCs at the source, while training them to be polymer chemists. ICPs have already shown promise in the biomedical field especially in the area of nerve regeneration and artificial muscles. A concerted effort will be made to include members of the research community at the nearby medical school in workshops and seminars so that future collaborative projects with our group may be possible.